thank.darwin wrote:I know what activation energy is and what it does but my question is - can activation energy be anything? (I know it can't be anything but what are the different kinds of activation energy?)

Saludos,

I just finished reading the section about activation energy and my textbook highlights that usually activation energy is thermal energy.

"Activation energy is often supplied in the form of heat that the reactant molecules absorb from the surroundings. The bonds of the reactants break only when the molecules have absorbed enough energy to become unstable and are therefore more reactive. The absorption of thermal energy increases the speed of the reactant molecules, so they collide more often and more forcefully. Also, thermal agitation of the atoms in the molecules makes the bonds more likely to break."

Furthermore, in biological systems high temperatures would harm the cell more than it would aid it. High temperatures kill cells and denatures proteins. That's why enzymes exist. They lower the amount of Activation Energy needed. This means that it lowers the amount of heat needed to activate a reaction. Therefore, reactions can still be executed within the cell at moderate temperatures.